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Papers by rosangela jacques

Engineering Structures, 2011

Flexible risers are presently seen as an attractive alternative to their rigid counterparts in th... more Flexible risers are presently seen as an attractive alternative to their rigid counterparts in the offshore oil exploration industry, mainly because of their relatively simpler mounting and transportation. However, the complex multi-layered structure which guarantees high flexural compliance is not favorable for inspection with most non-destructive testing (NDT) techniques, which makes structural integrity evaluation difficult. Initial efforts concentrated on the search for a single technique which would ensure reliable detection of armor failure, but recent studies have shown that the safest approach may be to take advantage of the redundancy obtained when different instruments are combined. This work presents results of a full-scale dynamic loading test of a 6 m-long section of a flexible pipe with end-fittings which was instrumented with a range of sensors. Of these, measurements of torsional angle variation, axial displacement and Acoustic Emission were selected for a direct comparison. A detection pattern is observed during forced rupture of the wires of one of the outer armor layers, and reliable identification of events is possible when information from the three techniques is combined.

Revista Ibero-Americana de Ciências Ambientais, 2020

O jambu (Spilanthes oleracea L.) pertence à família Asteraceae, nativa da Amazônia, de clima trop... more O jambu (Spilanthes oleracea L.) pertence à família Asteraceae, nativa da Amazônia, de clima tropical. Essa planta é uma hortaliça bastante cultivada e consumida na região Norte do Brasil, principalmente no Pará. Algumas de suas formas de utilização são nos restaurantes de comidas exóticas utilizando a inflorescência de jambu para compor seus pratos diferenciados na gas­tronomia. Entretanto o maior interesse nesta cultura é devido ao seu óleo essencial amplamente utilizado nas indústrias cosméticas e farmacêuticas. Nesta pesquisa, objetivou-se a obtenção e caracterização do óleo essencial de jambu cultivado de modo orgânico e convencional e seu possível efeito fungicida. O óleo essencial de folhas e inflorescências de duas cultivares (Jambuarana e Nazaré) foi obtido pela técnica de 'arraste a vapor d’água', usando um aparelho de Clevenger modificado e submetido, posteriormente, à análise por CG acoplada a um espectrômetro de massas CG-EM, a fim de analisar sua composição qu...

Journal of Environmental Chemical Engineering

Journal of Analytical and Applied Pyrolysis, 2018

Coffee bean tegument (silverskin) is a by-product derived from the coffee roasting process. This ... more Coffee bean tegument (silverskin) is a by-product derived from the coffee roasting process. This residue has been discarded, which constitutes a serious environmental problem. The depletion of oil reserves and environmental issues promoted by the combustion of fossil fuels has generated interest in the use of biomass to obtain fuel and chemicals products. The liquid product obtained by biomass pyrolysis is commonly called bio-oil. Bio-oil is a complex mixture of compounds, and its detailed chemical characterization is necessary to prospect its potential uses. Therefore, this study optimized the final temperature of pyrolysis and N 2 flow rate parameters for the pyrolysis of silverskin in a fixed bed reactor, by using a central composite design and response surface. The biooil chemical composition was evaluated by comprehensive two-dimensional gas chromatography coupled to rapid-scanning quadrupole mass spectrometry (GC × GC/qMS), combined with the use of standards and linear temperature-programmed retention indices (LTPRI). The optimal values calculated were 560°C for the final pyrolysis temperature and 49 mL min −1 for the N 2 flow rate. The organic phase yield was 15.2% under these conditions. At the optimal conditions, 228 compounds were identified (90.1% of the sample chromatographic volume) in the organic phase. The major chemical class, in terms of volume percentage, were the phenols (26.70%), followed by nitrogen compounds (18.51%). In addition, it is worth mentioning the high representability of the saturated hydrocarbons (8.28%), unsaturated aliphatic (6.69%), and aromatics (7.77%), which together account for 22.74% of the sample chromatographic volume. These results showed that the silverskin bio-oil may have the potential use as a source of chemical inputs.

Journal of the Brazilian Chemical Society, 2019

Piper glabratum is a plant native from South America, which has been little studied, despite its ... more Piper glabratum is a plant native from South America, which has been little studied, despite its use in folk medicine. In this study, chemical composition, antioxidant and antifungal activities of essential oils (EOs) from leaves of P. glabratum were investigated. The influence of seasonality on its chemical composition was also evaluated. The chemical characterization was performed by twodimensional gas chromatography coupled with quadrupole mass spectrometry (GC×GC/qMS). Altogether, 199 compounds were identified in the EOs and their composition varied during the seasonal cycle. The main compounds found were sesquiterpenes and their oxygenated analogues. EOs showed antioxidant activity, measured by 2,2-diphenyl-1-picrylhydrazyl-DPPH (from 28.1 to 33.4 µg mL-1) and β-carotene assays (from 57.4 to 66.4%), and inhibitory action against C. albicans. The oils provided expressive properties; however, the yield of EO from winter was not enough for activities assays, remarking the influence of the seasonality on the biological activities of this plant.

Journal of Environmental Chemical Engineering, 2018

The biochar is characterized by low surface area and, in order to their use as adsorbent it is po... more The biochar is characterized by low surface area and, in order to their use as adsorbent it is possible to use the activation process that allows to liberate and to increase the pores of the surface, increasing its sorption capacity. In the present work the activation of the biochar produced in the pyrolysis of agroindustrial residue (fiber) of the green coconut was studied, being done with sodium carbonate (Na2CO3) at high temperature. Biochar (BC) and activated biochar (ABC) were characterized and ABC was tested for use in the extraction of organic compounds present in the phenolic liquor, produced during the same pyrolysis process. The determination of the textural characteristics was done by N2 adsorption-desorption isotherms, obtaining an area of 1130 m 2 g-1 for the ABC, being superior to the area of commercial activated coals, with a total volume of pores of 0.55 cm 3 g-1. For the solid phase extraction (SPE) test, 500 mg of ABC were used in cartridges (equal to the commercial ones) obtaining a retention of about 100% of the organic compounds pre-existing in the sample, demonstrating the high adsorptive capacity of the activated biochar produced in this work. Desorption, as expected, had a lower performance than adsorption, being improved using ultrasonic bath, reaching values of the order of 40% recovery.

Journal of Environmental Chemical Engineering, 2018

In this study, a material with great adsorption potential was obtained from the residual cake fro... more In this study, a material with great adsorption potential was obtained from the residual cake from the extraction of energetic tobacco seeds. This residual cake seed was characterized and subjected to pyrolysis in nitrogen flow, resulting in bio-oil and biochar. The biochar and the feedstock (waste cake of tobacco seeds) were characterized by several techniques (thermogravimetric analysis (TGA), elemental analysis infrared spectroscopy, scanning electron microscopy, inductively coupled plasma optical emission spectrometry (ICP-OES), the Brunauer Emmet Teller (BET) method, the Barret, Joyner, and Halenda (BJH) method and functional density theory (DFT)) for comparison and subsequent possible application of the biochar. The results of the ICP-OES analyses indicate that nitrogen, potassium and phosphorus are the most abundant elements in the biomass and biochar. The metals analyses indicated no toxicological effects for animal feed. IR analysis results show that the pyrolysis led to conversion and/or removal of the vast majority of functional biomass groups, resulting in inorganic matter and inert carbon. The XPS analysis of the biochar indicates nitrogenous heteroaromatic structures which are formed during the pyrolysis process. In this way, can contribute to the cation exchange capacity in soils and adsorption of contaminants. Lastly, this biochar has great potential for use as an adsorbent for small molecules (due to the presence of micropores) after its activation, with a specific area of 1800 m 2 g-1 , surprisingly high compared with other solids of this type. Thus, a high value-added material can be obtained from the residue.

Energy & Fuels, 2017

Energetic tobacco (EnT) is a type of genetically modified tobacco with a focus on energy. Its see... more Energetic tobacco (EnT) is a type of genetically modified tobacco with a focus on energy. Its seeds are larger and appear in greater quantity than those of conventional tobacco. This plant easily adapts to unproductive soils and is practically free of nicotine. The oil seed from EnT can be used for producing biodiesel without competition with edible oils. Additionally, the resulting residual cake can be thermally degraded to bio-oil and biochar through pyrolysis processes. In this study, the fast pyrolysis (700°C at 100°C min −1) of the residual cake of EnT seeds was performed in a fixed bed reactor (quartz), yielding approximately 40% (in mass) liquid products (bio-oil and an aqueous phase). After removal of the aqueous phase, the organic phase was submitted to an acid−alkaline extraction of the N-compounds in a simple and efficient way. The bio-oil and alkaline extract were analyzed by comprehensive two-dimensional gas chromatography coupled to fast-quadrupole mass spectrometry. Compounds were tentatively identified by similarity with a commercial library of mass spectra and using retention indexes. The main classes of compounds identified were phenols, hydrocarbons, and N-compounds (imidazole, pyridine, and their derivatives), with the potential to be applied in the chemical and pharmaceutical industries as well as biofuel production. The alkaline extraction resulted in the isolation of the main N-components, a finding fundamental for the utilization of these compounds for the production of pharmaceuticals, pesticides, and polymers.

Química Nova, 2012

Recebido em 22/7/11; aceito em 5/2/12; publicado na web em 15/5/12 NAPHTHENIC ACIDS IN PETROLEUM.... more Recebido em 22/7/11; aceito em 5/2/12; publicado na web em 15/5/12 NAPHTHENIC ACIDS IN PETROLEUM. Brazilian petroleum is known by its high acidity due to the presence of acidic constituents, especially naphthenic acids (NA). The total characterization of the NA in petrochemical samples has been receiving special attention in research and comprises an analytical challenge, mainly due to the complexity of their mixtures. Gas chromatography with mass detector (GC/MS) is the technique of analysis more used, but recently comprehensive two-dimensional gas chromatography (GC × GC) has been used, due to its high resolution, peak capacity and sensitivity. The goal of this article is to discuss the techniques for sample preparation and analysis of NA in petroleum.

Journal of Analytical and Applied Pyrolysis, 2012

The use of bio oil of fast pyrolysis of agricultural and industrial residues may be an economical... more The use of bio oil of fast pyrolysis of agricultural and industrial residues may be an economically and environmentally friendly choice for generation of energy and also for the production of chemicals. Suitable applications of rice husk and peach pit are an important issue to avoid improper waste disposal, as Brazilian production of rice and peach reach significant values. The purpose of this work was to perform a detailed qualitative analysis of bio oils of rice husk and peach pit, taking advantage of the higher peak capacity, resolution, sensitivity and selectivity of two-dimensional gas chromatography with mass spectrometric detector (GC × GC/TOFMS). The total number of compounds detected by GC × GC/TOFMS was 503 and 705 for rice husk and peach pit pyrolysates, respectively. Compounds tentatively identified in the same matrices were 106 and 223, respectively. Bio oil compounds were classified in five groups: phenols ketones, acids, ethers, aldehydes, and others. Major classes of both bio oils were phenols and ketones and the major compounds of rice husk and peach pit pyrolysates were guaiacol and furfural, respectively. Twenty compounds (area > 1%) of rice husk bio oil and 25 of peach pit oil accounted for 74.04% and 63.62% of the total area, respectively. A structured distribution of compounds of some classes was observed in the two dimensional space, as for example phenols and ketones. Qualitative analysis of these bio oils by GC × GC provided a detailed knowledge of their composition. Both bio oils showed might be employed for the production of chemicals and may be upgraded through an improved pyrolysis process.

Industrial Crops and Products, 2014

Soft laser photo-ionization mass spectroemtry is presented as a separation dimension hyphenated w... more Soft laser photo-ionization mass spectroemtry is presented as a separation dimension hyphenated with gas chromatographic techniques. Single photon ionization (SPI) is a universal soft ionization method which ionizes organic molecules with an ionization potential below 10.5 eV if 118 nm laser radiation is used. The inherently soft ionization of photo ionization techniques can further be utilized together with gas chromatography as a comprehensive two-dimensional separation method (GC × MS), using the GC retention time as first separation dimension and the molecular mass as second separation dimension. Some GC × MS chromatograms of diesel petroleum samples using SPI are presented and discussed. Finally, it is demonstrated that the coupling of soft SPI mass spectrometry with comprehensive two-dimensional gas chromatography (GC × GC) provides a three-dimensional separation technique (GC × GC × SPI-MS).

Anal. Methods, 2014

ABSTRACT

À professora Ora. Elina Bastos Caramão pela amizade, orientação, dedicação e incentivo especialme... more À professora Ora. Elina Bastos Caramão pela amizade, orientação, dedicação e incentivo especialmente nos momentos mais difíceis deste trabalho. Aos professores Or. José Vladimir de Oliveira e Or. Cláudio Oariva, supervisores do trabalho desenvolvido na Universidade Regional Integrada do Alto Uruguai e Missões, Campus de Erechim, pela amizade, incentivo, dedicação e valiosas contribuições. Aos colegas e amigos do Curso, em especial a Inês, Valéria, Cecília e Fernanda pelo companheirismo e pelas sugestões e observações valiosas. À Anelise Schmidt e Flávio Pavan pela amizade. Aos bolsistas de iniciação científica Ana Paula, Rafael, Jonathan, Bruna e Camila que realizaram um trabalho sério e responsável, pela amizade e companheirismo. Aos demais alunos do Laboratório E-202 pela colaboração e amizade. Aos demais professores e funcionários do Instituto de Química da UFRGS, pelo apoio técnico. Ao Or. Sérgio do Amaral professor da URI-campus de Erechim, pela contribuição na discussão das variáveis agronômicas da erva-mate. À Eunice Valduga pela prestatividade, amizade e profissionalismo. À Rositânia, funcionária da URI-campus de Erechim, pela amizade, incentivo, e apoio técnico. Rosângela Assis Jacques v PPGQ-UFRGS-TESE DE DOUTORADO À toda a família da prof. Elina que me acolheu carinhosa e cuidadosamente, com verdadeira amizade, durante a execução da parte escrita deste trabalho. À Ervateira Barão pelo plantio da erva-mate e cuidados com a colheita das plantas utilizadas neste estudo. Aos amigos do Instituto de Química da UPRGS e a todos aqueles que de uma forma ou de outra contribuíram para a realização deste trabalho.

Sensors and Actuators Reports

Resumo: O jambu (Spilanthes oleracea) pertence à família Asteraceae, nativa da Amazônia, de clima... more Resumo: O jambu (Spilanthes oleracea) pertence à família Asteraceae, nativa da Amazônia, de clima tropical. O jambu possui em torno de 0,7 % de óleo essencial, que está sendo fornecido direto para as indústrias de cosméticos, pela sua qualidade farmacológica. Esse efeito farmacológico se deve as suas substâncias químicas, dentre as quais, trans-cariofileno, germacreno D, L-dodeceno, espatulenol e espilantol. Nesta pesquisa, objetivou-se a obtenção e caracterização do óleo essencial de jambu. O óleo essencial foi obtido pela técnica “arraste a vapor d’água”, utilizando-se de um aparelho de Clevenger modificado e submetido, posteriormente, à análise por cromatografia gasosa acoplada a um espectrômetro de massas CG-EM, a fim de investigar sua composição. Conclui-se que o óleo essencial da espécie Spilanthes oleracea, apresenta constituição química bastante estável para cv. Jambuarana, apresentando um total de 66 substâncias. Esse perfil cromatográfico candidata esta espécie como uma pr...

Microchemical Journal, 2021

Abstract This paper reports the quantification of total phenolic compounds and caffeine in green ... more Abstract This paper reports the quantification of total phenolic compounds and caffeine in green and black tea using fluorescence, medium (MIR), and near (NIR) infrared spectroscopy combined with spectral variables selection tools (wavenumber or excitation/emission pairs). Nineteen tea samples were analyzed with a traditional analytical method for phenolic (Folin-Ciocalteu) and the content was expressed as milligrams of Gallic Acid Equivalent per gram of the sample (mg GAE g−1 dry basis). Caffeine quantification was performed by high-performance liquid chromatography. To optimize the variable selection and predict total phenolic and caffeine content, we applied a Pure Spectra chemometric Modeling (PSCM). The predictive quality of the models was assessed using metrics: Root Mean Square Error (RMSE), Mean Absolute Error (MAPE) and Determination Coefficient (R2). The spectroscopic techniques fluorescence, MIR, and NIR presented comparable metrics. Using only 4 variables, RMSE was less than 5.82 mg GAE g−1 for the Test subset to predict total phenolic compounds and 1.79 mg g−1 to predict caffeine. This work demonstrated that fluorescence, MIR, and NIR spectroscopy with the PSCM algorithm could be used to analyze the content of total phenolic compounds and caffeine quickly and non-destructively, using a small number of variables.

Bioprocess and Biosystems Engineering, 2020

Lipases CAL-B, TLL, and RML were used in the synthesis of free fatty acids of grape seed oil as h... more Lipases CAL-B, TLL, and RML were used in the synthesis of free fatty acids of grape seed oil as heterogeneous substrate. The best enzyme was used to optimize the reaction variables temperature, enzyme content, and molar ratio of water:oil in batch reactions using experimental planning. The ideal conditions to produce free fatty acids using pure RML were 45 °C, 12:1 substrate molar ratio, and 15% enzyme, resulting in 66% of oil hydrolysis and a productivity of 0.54 mol L −1 min −1 in 4 h of reaction at 180 rpm. Repeated batches of reaction were performed testing the operational stability of RML, results showing that this enzyme could be used for at least 20 cycles keeping more than 80% of its initial activity, suggesting its potential use in industrial processes. The synthesis of free fatty acids was then evaluated in continuous reactions using packed-bed reactor (PBR). The highest productivity in the continuous process was 6.85 mol L −1 min −1 , using only RML, showing an operational stability higher than 80% of its initial conversion capacity after 11 days of operation, at a flow rate of 0.13 mL min −1 at 45 °C. We evaluated the use of this hydrolyzed oil as substrate for lactone bioproduction using Galactomyces geotrichum UFMG-CM-Y3276, G. geotrichum UFMG-CM-Y3558, and Geotrichum klebahnii UFMG-CM-Y3014 screened for their oil-hydrolysis ability. Volatile compounds were qualitatively identified in GC-MS as γ-octalactone and γ-nonalactone.

AoB PLANTS, 2018

Petunia is endemic to South America grasslands; member of this genus exhibit variation in flower ... more Petunia is endemic to South America grasslands; member of this genus exhibit variation in flower colour and shape, attracting bees, hawkmoths or hummingbirds. This group of plants is thus an excellent model system for evolutionary studies of diversification associated with pollinator shifts. Our aims were to identify the legitimate pollinator of Petunia secreta, a rare and endemic species, and to assess the importance of floral traits in pollinator attraction in this Petunia species. To determine the legitimate pollinator, field observations were conducted, and all floral visitors were recorded and evaluated. We also measured the nectar volume and sugar concentration. To characterize morphological cues for pollinators, we assessed the ultraviolet (UV)-light response in detached flowers, and characterized the floral pigments and pollen volatile scents for four different Petunia species that present different pollination syndromes. Petunia secreta shares the most recent ancestor with a white hawkmoth-pollinated species, P. axillaris, but presents flavonols and anthocyanin pigments responsible for the pink corolla colour and UV-light responses that are common to bee-pollinated Petunia species. Our study showed that a solitary bee in the genus Pseudagapostemon was the most frequent pollinator of P. secreta, and these bees collect only pollen as a reward. Despite being mainly bee-pollinated, different functional groups of pollinators visit P. secreta. Nectar volume, sugar concentration per flower, morphology and components of pollen scent would appear to be attractive to several different pollinator groups. Notably, the corolla includes a narrow tube with nectar at its base that cannot be reached by Pseudagapostemon, and flowers of P. secreta appear to follow an evolutionary transition, with traits attractive to several functional groups of pollinators. Additionally, the present study shows that differences in the volatiles of pollen scent are relevant for plant mutualistic and antagonist interactions in Petunia species and that pollen scent profile plays a key role in characterizing pollination syndromes.

Renewable Energy, 2018

Pyrolysis of rice husk (RH) is an efficient process for the transformation of biomass to bio-oil ... more Pyrolysis of rice husk (RH) is an efficient process for the transformation of biomass to bio-oil (high-added value product). Bio-oil consists of two immiscible phases (organic and aqueous) both with potential for the generation of important chemicals for the industry. The aim of this study was to produce bio-oil by pyrolysis of RH and elucidate its chemical composition. Response surface methodology (RSM) was successfully used to determine the optimal pyrolysis conditions for the RH dry bio-oil production using central composite design (CCD). Temperature and flow rate significantly affected the bio-oil production and higher dry bio-oil yield was achieved at 650 C and N 2 flow rate of 100 mL min À1 (predicted values of 16.9%). High performance liquid chromatography with photodiode array detection (HPLC/PDA) and comprehensive two-dimensional gas chromatography with quadrupole mass spectrometry detection (GC Â GC/qMS) were used to provide a comprehensive characterization (qualitative and quantitative) of both phases from RH bio-oil. Through GC Â GC/qMS analysis a total number of 98 compounds were found in organic phase; from these, 62 were quantified using a developed quantitative method by relative response factors (RRFs). Phenols and ketones (cyclic ketones) were majority in the organic phase, 8.21 and 5.90 wt%, respectively, and the benzofuran (1.37 wt%) corresponds to the major identified compound. HPLC/PDA analysis evidenced a high concentration of benzenediols and furfurals in the aqueous phase. Catechol was the major compound (2063 mg L À1) followed by furfural (997 mg L À1) and hydroquinone (899 mg L À1). This is the first time that GC Â GC/qMS and HPLC/PDA has been used to characterize (qualitatively and quantitatively) both phases from RH bio-oil which showed potential use as a source of high-added value chemicals.

Phytochemical analysis : PCA, Jan 26, 2018

Piper amalago has a distribution from Mexico to Brazil; their aerial parts have been used in folk... more Piper amalago has a distribution from Mexico to Brazil; their aerial parts have been used in folk medicine to treat diuretic and kidney diseases. The purpose of this study was to obtain a deeper understanding of the chemical composition of essential oils (EOs) extracted from both the leaves and stems of P. amalago, compare them, and evaluate their antilithiasic activity and acute toxicity. Extraction was performed by hydrodistillation, whereas chemical characterisation by two-dimensional gas chromatography coupled with rapid-scanning quadrupole mass spectrometry (GC×GC/qMS). The antilithiasic activity was evaluated by the effect of the EOs on calcium oxalate crystallisation in vitro. The turbidity index and the number of crystals formed were determined and used as an estimative of the activity. In the acute toxicity assay, the effects of a single oral dose of the EOs in Wistar rats were determined. General behaviour, adverse effects, and mortality were determined. A total of 322 com...

Engineering Structures, 2011

Flexible risers are presently seen as an attractive alternative to their rigid counterparts in th... more Flexible risers are presently seen as an attractive alternative to their rigid counterparts in the offshore oil exploration industry, mainly because of their relatively simpler mounting and transportation. However, the complex multi-layered structure which guarantees high flexural compliance is not favorable for inspection with most non-destructive testing (NDT) techniques, which makes structural integrity evaluation difficult. Initial efforts concentrated on the search for a single technique which would ensure reliable detection of armor failure, but recent studies have shown that the safest approach may be to take advantage of the redundancy obtained when different instruments are combined. This work presents results of a full-scale dynamic loading test of a 6 m-long section of a flexible pipe with end-fittings which was instrumented with a range of sensors. Of these, measurements of torsional angle variation, axial displacement and Acoustic Emission were selected for a direct comparison. A detection pattern is observed during forced rupture of the wires of one of the outer armor layers, and reliable identification of events is possible when information from the three techniques is combined.

Revista Ibero-Americana de Ciências Ambientais, 2020

O jambu (Spilanthes oleracea L.) pertence à família Asteraceae, nativa da Amazônia, de clima trop... more O jambu (Spilanthes oleracea L.) pertence à família Asteraceae, nativa da Amazônia, de clima tropical. Essa planta é uma hortaliça bastante cultivada e consumida na região Norte do Brasil, principalmente no Pará. Algumas de suas formas de utilização são nos restaurantes de comidas exóticas utilizando a inflorescência de jambu para compor seus pratos diferenciados na gas­tronomia. Entretanto o maior interesse nesta cultura é devido ao seu óleo essencial amplamente utilizado nas indústrias cosméticas e farmacêuticas. Nesta pesquisa, objetivou-se a obtenção e caracterização do óleo essencial de jambu cultivado de modo orgânico e convencional e seu possível efeito fungicida. O óleo essencial de folhas e inflorescências de duas cultivares (Jambuarana e Nazaré) foi obtido pela técnica de 'arraste a vapor d’água', usando um aparelho de Clevenger modificado e submetido, posteriormente, à análise por CG acoplada a um espectrômetro de massas CG-EM, a fim de analisar sua composição qu...

Journal of Environmental Chemical Engineering

Journal of Analytical and Applied Pyrolysis, 2018

Coffee bean tegument (silverskin) is a by-product derived from the coffee roasting process. This ... more Coffee bean tegument (silverskin) is a by-product derived from the coffee roasting process. This residue has been discarded, which constitutes a serious environmental problem. The depletion of oil reserves and environmental issues promoted by the combustion of fossil fuels has generated interest in the use of biomass to obtain fuel and chemicals products. The liquid product obtained by biomass pyrolysis is commonly called bio-oil. Bio-oil is a complex mixture of compounds, and its detailed chemical characterization is necessary to prospect its potential uses. Therefore, this study optimized the final temperature of pyrolysis and N 2 flow rate parameters for the pyrolysis of silverskin in a fixed bed reactor, by using a central composite design and response surface. The biooil chemical composition was evaluated by comprehensive two-dimensional gas chromatography coupled to rapid-scanning quadrupole mass spectrometry (GC × GC/qMS), combined with the use of standards and linear temperature-programmed retention indices (LTPRI). The optimal values calculated were 560°C for the final pyrolysis temperature and 49 mL min −1 for the N 2 flow rate. The organic phase yield was 15.2% under these conditions. At the optimal conditions, 228 compounds were identified (90.1% of the sample chromatographic volume) in the organic phase. The major chemical class, in terms of volume percentage, were the phenols (26.70%), followed by nitrogen compounds (18.51%). In addition, it is worth mentioning the high representability of the saturated hydrocarbons (8.28%), unsaturated aliphatic (6.69%), and aromatics (7.77%), which together account for 22.74% of the sample chromatographic volume. These results showed that the silverskin bio-oil may have the potential use as a source of chemical inputs.

Journal of the Brazilian Chemical Society, 2019

Piper glabratum is a plant native from South America, which has been little studied, despite its ... more Piper glabratum is a plant native from South America, which has been little studied, despite its use in folk medicine. In this study, chemical composition, antioxidant and antifungal activities of essential oils (EOs) from leaves of P. glabratum were investigated. The influence of seasonality on its chemical composition was also evaluated. The chemical characterization was performed by twodimensional gas chromatography coupled with quadrupole mass spectrometry (GC×GC/qMS). Altogether, 199 compounds were identified in the EOs and their composition varied during the seasonal cycle. The main compounds found were sesquiterpenes and their oxygenated analogues. EOs showed antioxidant activity, measured by 2,2-diphenyl-1-picrylhydrazyl-DPPH (from 28.1 to 33.4 µg mL-1) and β-carotene assays (from 57.4 to 66.4%), and inhibitory action against C. albicans. The oils provided expressive properties; however, the yield of EO from winter was not enough for activities assays, remarking the influence of the seasonality on the biological activities of this plant.

Journal of Environmental Chemical Engineering, 2018

The biochar is characterized by low surface area and, in order to their use as adsorbent it is po... more The biochar is characterized by low surface area and, in order to their use as adsorbent it is possible to use the activation process that allows to liberate and to increase the pores of the surface, increasing its sorption capacity. In the present work the activation of the biochar produced in the pyrolysis of agroindustrial residue (fiber) of the green coconut was studied, being done with sodium carbonate (Na2CO3) at high temperature. Biochar (BC) and activated biochar (ABC) were characterized and ABC was tested for use in the extraction of organic compounds present in the phenolic liquor, produced during the same pyrolysis process. The determination of the textural characteristics was done by N2 adsorption-desorption isotherms, obtaining an area of 1130 m 2 g-1 for the ABC, being superior to the area of commercial activated coals, with a total volume of pores of 0.55 cm 3 g-1. For the solid phase extraction (SPE) test, 500 mg of ABC were used in cartridges (equal to the commercial ones) obtaining a retention of about 100% of the organic compounds pre-existing in the sample, demonstrating the high adsorptive capacity of the activated biochar produced in this work. Desorption, as expected, had a lower performance than adsorption, being improved using ultrasonic bath, reaching values of the order of 40% recovery.

Journal of Environmental Chemical Engineering, 2018

In this study, a material with great adsorption potential was obtained from the residual cake fro... more In this study, a material with great adsorption potential was obtained from the residual cake from the extraction of energetic tobacco seeds. This residual cake seed was characterized and subjected to pyrolysis in nitrogen flow, resulting in bio-oil and biochar. The biochar and the feedstock (waste cake of tobacco seeds) were characterized by several techniques (thermogravimetric analysis (TGA), elemental analysis infrared spectroscopy, scanning electron microscopy, inductively coupled plasma optical emission spectrometry (ICP-OES), the Brunauer Emmet Teller (BET) method, the Barret, Joyner, and Halenda (BJH) method and functional density theory (DFT)) for comparison and subsequent possible application of the biochar. The results of the ICP-OES analyses indicate that nitrogen, potassium and phosphorus are the most abundant elements in the biomass and biochar. The metals analyses indicated no toxicological effects for animal feed. IR analysis results show that the pyrolysis led to conversion and/or removal of the vast majority of functional biomass groups, resulting in inorganic matter and inert carbon. The XPS analysis of the biochar indicates nitrogenous heteroaromatic structures which are formed during the pyrolysis process. In this way, can contribute to the cation exchange capacity in soils and adsorption of contaminants. Lastly, this biochar has great potential for use as an adsorbent for small molecules (due to the presence of micropores) after its activation, with a specific area of 1800 m 2 g-1 , surprisingly high compared with other solids of this type. Thus, a high value-added material can be obtained from the residue.

Energy & Fuels, 2017

Energetic tobacco (EnT) is a type of genetically modified tobacco with a focus on energy. Its see... more Energetic tobacco (EnT) is a type of genetically modified tobacco with a focus on energy. Its seeds are larger and appear in greater quantity than those of conventional tobacco. This plant easily adapts to unproductive soils and is practically free of nicotine. The oil seed from EnT can be used for producing biodiesel without competition with edible oils. Additionally, the resulting residual cake can be thermally degraded to bio-oil and biochar through pyrolysis processes. In this study, the fast pyrolysis (700°C at 100°C min −1) of the residual cake of EnT seeds was performed in a fixed bed reactor (quartz), yielding approximately 40% (in mass) liquid products (bio-oil and an aqueous phase). After removal of the aqueous phase, the organic phase was submitted to an acid−alkaline extraction of the N-compounds in a simple and efficient way. The bio-oil and alkaline extract were analyzed by comprehensive two-dimensional gas chromatography coupled to fast-quadrupole mass spectrometry. Compounds were tentatively identified by similarity with a commercial library of mass spectra and using retention indexes. The main classes of compounds identified were phenols, hydrocarbons, and N-compounds (imidazole, pyridine, and their derivatives), with the potential to be applied in the chemical and pharmaceutical industries as well as biofuel production. The alkaline extraction resulted in the isolation of the main N-components, a finding fundamental for the utilization of these compounds for the production of pharmaceuticals, pesticides, and polymers.

Química Nova, 2012

Recebido em 22/7/11; aceito em 5/2/12; publicado na web em 15/5/12 NAPHTHENIC ACIDS IN PETROLEUM.... more Recebido em 22/7/11; aceito em 5/2/12; publicado na web em 15/5/12 NAPHTHENIC ACIDS IN PETROLEUM. Brazilian petroleum is known by its high acidity due to the presence of acidic constituents, especially naphthenic acids (NA). The total characterization of the NA in petrochemical samples has been receiving special attention in research and comprises an analytical challenge, mainly due to the complexity of their mixtures. Gas chromatography with mass detector (GC/MS) is the technique of analysis more used, but recently comprehensive two-dimensional gas chromatography (GC × GC) has been used, due to its high resolution, peak capacity and sensitivity. The goal of this article is to discuss the techniques for sample preparation and analysis of NA in petroleum.

Journal of Analytical and Applied Pyrolysis, 2012

The use of bio oil of fast pyrolysis of agricultural and industrial residues may be an economical... more The use of bio oil of fast pyrolysis of agricultural and industrial residues may be an economically and environmentally friendly choice for generation of energy and also for the production of chemicals. Suitable applications of rice husk and peach pit are an important issue to avoid improper waste disposal, as Brazilian production of rice and peach reach significant values. The purpose of this work was to perform a detailed qualitative analysis of bio oils of rice husk and peach pit, taking advantage of the higher peak capacity, resolution, sensitivity and selectivity of two-dimensional gas chromatography with mass spectrometric detector (GC × GC/TOFMS). The total number of compounds detected by GC × GC/TOFMS was 503 and 705 for rice husk and peach pit pyrolysates, respectively. Compounds tentatively identified in the same matrices were 106 and 223, respectively. Bio oil compounds were classified in five groups: phenols ketones, acids, ethers, aldehydes, and others. Major classes of both bio oils were phenols and ketones and the major compounds of rice husk and peach pit pyrolysates were guaiacol and furfural, respectively. Twenty compounds (area > 1%) of rice husk bio oil and 25 of peach pit oil accounted for 74.04% and 63.62% of the total area, respectively. A structured distribution of compounds of some classes was observed in the two dimensional space, as for example phenols and ketones. Qualitative analysis of these bio oils by GC × GC provided a detailed knowledge of their composition. Both bio oils showed might be employed for the production of chemicals and may be upgraded through an improved pyrolysis process.

Industrial Crops and Products, 2014

Soft laser photo-ionization mass spectroemtry is presented as a separation dimension hyphenated w... more Soft laser photo-ionization mass spectroemtry is presented as a separation dimension hyphenated with gas chromatographic techniques. Single photon ionization (SPI) is a universal soft ionization method which ionizes organic molecules with an ionization potential below 10.5 eV if 118 nm laser radiation is used. The inherently soft ionization of photo ionization techniques can further be utilized together with gas chromatography as a comprehensive two-dimensional separation method (GC × MS), using the GC retention time as first separation dimension and the molecular mass as second separation dimension. Some GC × MS chromatograms of diesel petroleum samples using SPI are presented and discussed. Finally, it is demonstrated that the coupling of soft SPI mass spectrometry with comprehensive two-dimensional gas chromatography (GC × GC) provides a three-dimensional separation technique (GC × GC × SPI-MS).

Anal. Methods, 2014

ABSTRACT

À professora Ora. Elina Bastos Caramão pela amizade, orientação, dedicação e incentivo especialme... more À professora Ora. Elina Bastos Caramão pela amizade, orientação, dedicação e incentivo especialmente nos momentos mais difíceis deste trabalho. Aos professores Or. José Vladimir de Oliveira e Or. Cláudio Oariva, supervisores do trabalho desenvolvido na Universidade Regional Integrada do Alto Uruguai e Missões, Campus de Erechim, pela amizade, incentivo, dedicação e valiosas contribuições. Aos colegas e amigos do Curso, em especial a Inês, Valéria, Cecília e Fernanda pelo companheirismo e pelas sugestões e observações valiosas. À Anelise Schmidt e Flávio Pavan pela amizade. Aos bolsistas de iniciação científica Ana Paula, Rafael, Jonathan, Bruna e Camila que realizaram um trabalho sério e responsável, pela amizade e companheirismo. Aos demais alunos do Laboratório E-202 pela colaboração e amizade. Aos demais professores e funcionários do Instituto de Química da UFRGS, pelo apoio técnico. Ao Or. Sérgio do Amaral professor da URI-campus de Erechim, pela contribuição na discussão das variáveis agronômicas da erva-mate. À Eunice Valduga pela prestatividade, amizade e profissionalismo. À Rositânia, funcionária da URI-campus de Erechim, pela amizade, incentivo, e apoio técnico. Rosângela Assis Jacques v PPGQ-UFRGS-TESE DE DOUTORADO À toda a família da prof. Elina que me acolheu carinhosa e cuidadosamente, com verdadeira amizade, durante a execução da parte escrita deste trabalho. À Ervateira Barão pelo plantio da erva-mate e cuidados com a colheita das plantas utilizadas neste estudo. Aos amigos do Instituto de Química da UPRGS e a todos aqueles que de uma forma ou de outra contribuíram para a realização deste trabalho.

Sensors and Actuators Reports

Resumo: O jambu (Spilanthes oleracea) pertence à família Asteraceae, nativa da Amazônia, de clima... more Resumo: O jambu (Spilanthes oleracea) pertence à família Asteraceae, nativa da Amazônia, de clima tropical. O jambu possui em torno de 0,7 % de óleo essencial, que está sendo fornecido direto para as indústrias de cosméticos, pela sua qualidade farmacológica. Esse efeito farmacológico se deve as suas substâncias químicas, dentre as quais, trans-cariofileno, germacreno D, L-dodeceno, espatulenol e espilantol. Nesta pesquisa, objetivou-se a obtenção e caracterização do óleo essencial de jambu. O óleo essencial foi obtido pela técnica “arraste a vapor d’água”, utilizando-se de um aparelho de Clevenger modificado e submetido, posteriormente, à análise por cromatografia gasosa acoplada a um espectrômetro de massas CG-EM, a fim de investigar sua composição. Conclui-se que o óleo essencial da espécie Spilanthes oleracea, apresenta constituição química bastante estável para cv. Jambuarana, apresentando um total de 66 substâncias. Esse perfil cromatográfico candidata esta espécie como uma pr...

Microchemical Journal, 2021

Abstract This paper reports the quantification of total phenolic compounds and caffeine in green ... more Abstract This paper reports the quantification of total phenolic compounds and caffeine in green and black tea using fluorescence, medium (MIR), and near (NIR) infrared spectroscopy combined with spectral variables selection tools (wavenumber or excitation/emission pairs). Nineteen tea samples were analyzed with a traditional analytical method for phenolic (Folin-Ciocalteu) and the content was expressed as milligrams of Gallic Acid Equivalent per gram of the sample (mg GAE g−1 dry basis). Caffeine quantification was performed by high-performance liquid chromatography. To optimize the variable selection and predict total phenolic and caffeine content, we applied a Pure Spectra chemometric Modeling (PSCM). The predictive quality of the models was assessed using metrics: Root Mean Square Error (RMSE), Mean Absolute Error (MAPE) and Determination Coefficient (R2). The spectroscopic techniques fluorescence, MIR, and NIR presented comparable metrics. Using only 4 variables, RMSE was less than 5.82 mg GAE g−1 for the Test subset to predict total phenolic compounds and 1.79 mg g−1 to predict caffeine. This work demonstrated that fluorescence, MIR, and NIR spectroscopy with the PSCM algorithm could be used to analyze the content of total phenolic compounds and caffeine quickly and non-destructively, using a small number of variables.

Bioprocess and Biosystems Engineering, 2020

Lipases CAL-B, TLL, and RML were used in the synthesis of free fatty acids of grape seed oil as h... more Lipases CAL-B, TLL, and RML were used in the synthesis of free fatty acids of grape seed oil as heterogeneous substrate. The best enzyme was used to optimize the reaction variables temperature, enzyme content, and molar ratio of water:oil in batch reactions using experimental planning. The ideal conditions to produce free fatty acids using pure RML were 45 °C, 12:1 substrate molar ratio, and 15% enzyme, resulting in 66% of oil hydrolysis and a productivity of 0.54 mol L −1 min −1 in 4 h of reaction at 180 rpm. Repeated batches of reaction were performed testing the operational stability of RML, results showing that this enzyme could be used for at least 20 cycles keeping more than 80% of its initial activity, suggesting its potential use in industrial processes. The synthesis of free fatty acids was then evaluated in continuous reactions using packed-bed reactor (PBR). The highest productivity in the continuous process was 6.85 mol L −1 min −1 , using only RML, showing an operational stability higher than 80% of its initial conversion capacity after 11 days of operation, at a flow rate of 0.13 mL min −1 at 45 °C. We evaluated the use of this hydrolyzed oil as substrate for lactone bioproduction using Galactomyces geotrichum UFMG-CM-Y3276, G. geotrichum UFMG-CM-Y3558, and Geotrichum klebahnii UFMG-CM-Y3014 screened for their oil-hydrolysis ability. Volatile compounds were qualitatively identified in GC-MS as γ-octalactone and γ-nonalactone.

AoB PLANTS, 2018

Petunia is endemic to South America grasslands; member of this genus exhibit variation in flower ... more Petunia is endemic to South America grasslands; member of this genus exhibit variation in flower colour and shape, attracting bees, hawkmoths or hummingbirds. This group of plants is thus an excellent model system for evolutionary studies of diversification associated with pollinator shifts. Our aims were to identify the legitimate pollinator of Petunia secreta, a rare and endemic species, and to assess the importance of floral traits in pollinator attraction in this Petunia species. To determine the legitimate pollinator, field observations were conducted, and all floral visitors were recorded and evaluated. We also measured the nectar volume and sugar concentration. To characterize morphological cues for pollinators, we assessed the ultraviolet (UV)-light response in detached flowers, and characterized the floral pigments and pollen volatile scents for four different Petunia species that present different pollination syndromes. Petunia secreta shares the most recent ancestor with a white hawkmoth-pollinated species, P. axillaris, but presents flavonols and anthocyanin pigments responsible for the pink corolla colour and UV-light responses that are common to bee-pollinated Petunia species. Our study showed that a solitary bee in the genus Pseudagapostemon was the most frequent pollinator of P. secreta, and these bees collect only pollen as a reward. Despite being mainly bee-pollinated, different functional groups of pollinators visit P. secreta. Nectar volume, sugar concentration per flower, morphology and components of pollen scent would appear to be attractive to several different pollinator groups. Notably, the corolla includes a narrow tube with nectar at its base that cannot be reached by Pseudagapostemon, and flowers of P. secreta appear to follow an evolutionary transition, with traits attractive to several functional groups of pollinators. Additionally, the present study shows that differences in the volatiles of pollen scent are relevant for plant mutualistic and antagonist interactions in Petunia species and that pollen scent profile plays a key role in characterizing pollination syndromes.

Renewable Energy, 2018

Pyrolysis of rice husk (RH) is an efficient process for the transformation of biomass to bio-oil ... more Pyrolysis of rice husk (RH) is an efficient process for the transformation of biomass to bio-oil (high-added value product). Bio-oil consists of two immiscible phases (organic and aqueous) both with potential for the generation of important chemicals for the industry. The aim of this study was to produce bio-oil by pyrolysis of RH and elucidate its chemical composition. Response surface methodology (RSM) was successfully used to determine the optimal pyrolysis conditions for the RH dry bio-oil production using central composite design (CCD). Temperature and flow rate significantly affected the bio-oil production and higher dry bio-oil yield was achieved at 650 C and N 2 flow rate of 100 mL min À1 (predicted values of 16.9%). High performance liquid chromatography with photodiode array detection (HPLC/PDA) and comprehensive two-dimensional gas chromatography with quadrupole mass spectrometry detection (GC Â GC/qMS) were used to provide a comprehensive characterization (qualitative and quantitative) of both phases from RH bio-oil. Through GC Â GC/qMS analysis a total number of 98 compounds were found in organic phase; from these, 62 were quantified using a developed quantitative method by relative response factors (RRFs). Phenols and ketones (cyclic ketones) were majority in the organic phase, 8.21 and 5.90 wt%, respectively, and the benzofuran (1.37 wt%) corresponds to the major identified compound. HPLC/PDA analysis evidenced a high concentration of benzenediols and furfurals in the aqueous phase. Catechol was the major compound (2063 mg L À1) followed by furfural (997 mg L À1) and hydroquinone (899 mg L À1). This is the first time that GC Â GC/qMS and HPLC/PDA has been used to characterize (qualitatively and quantitatively) both phases from RH bio-oil which showed potential use as a source of high-added value chemicals.

Phytochemical analysis : PCA, Jan 26, 2018

Piper amalago has a distribution from Mexico to Brazil; their aerial parts have been used in folk... more Piper amalago has a distribution from Mexico to Brazil; their aerial parts have been used in folk medicine to treat diuretic and kidney diseases. The purpose of this study was to obtain a deeper understanding of the chemical composition of essential oils (EOs) extracted from both the leaves and stems of P. amalago, compare them, and evaluate their antilithiasic activity and acute toxicity. Extraction was performed by hydrodistillation, whereas chemical characterisation by two-dimensional gas chromatography coupled with rapid-scanning quadrupole mass spectrometry (GC×GC/qMS). The antilithiasic activity was evaluated by the effect of the EOs on calcium oxalate crystallisation in vitro. The turbidity index and the number of crystals formed were determined and used as an estimative of the activity. In the acute toxicity assay, the effects of a single oral dose of the EOs in Wistar rats were determined. General behaviour, adverse effects, and mortality were determined. A total of 322 com...